This invention relates generally to medical devices, systems, and methods, and more particularly to sterile drapes or covers for slit lamps used to illuminate and view an anterior segment of an eye.
Slit lamps are used in ophthalmic applications to view an anterior segment of an eye with a beam of light. The anterior segment of interest typically comprises a cornea, an iris, a sclera, an anterior lens capsule, a posterior lens capsule, and/or a lens nucleus. A beam of light can illuminate these tissues while an operator views the illuminated area by direct examination or through a magnification optic such as a microscope.
The beam of light from a slit lamp can have a varying beam cross section. For example, in some instances the beam is desirably focused to form a narrow slit. Such a beam is desirable for examining layers of a cornea of an eye. In other instances, for example when viewing a large area of an eye, an operator adjusts the beam to have a wide beam cross section. Slit lamps often pass light through a slot aperture. The variation in size of the light beam can be, for example, accomplished by mechanically changing a width across a slot aperture.
During LASIK refractive laser surgery a surgeon generally makes a corneal flap with a microkeratome. The surgeon is typically gloved and sterile during LASIK. After a flap is lifted, the refractive laser treatment is performed on the underlying stroma, and then the flap is laid back onto the stromal bed. The refractive laser surgeon will often move the patient from the laser system treatment chair to a commercial slit lamp, where the surgeon evaluates repositioning of the LASIK flap. The beam from the slit lamp may also be well suited for viewing any debris under the LASIK flap, and for viewing any wrinkles in the LASIK flap. Debris and flap wrinkles can then be appropriately treated and corrected.
U.S. patent application Ser. No. 10/876,268, filed on Jun. 23, 2004 and entitled “Sterile Hand Held Refractive Surgery Slit Lamp Illumination System” (the full disclosure of which is incorporated herein by reference) describes a slit lamp system which may be particularly well suited for laser eye surgery. While this system may present significant advantages for use in examining refractive tissues within a sterile field associated with refractive surgery, still further advancements and improvements might be desirable. In particular, known sterile surgical covers may not be ideally suited for use during laser eye surgery and ophthalmic examinations. In general, sterile covers providing improved ease of use without compromising sterility and without increasing complexity or costs would be beneficial.